636 PROCEEDINGS 0^ THE GEOLOGICAL SOCIETY. [JunC 17, 



curved commencing with a small radicle and a slender curved 

 proximal portion, which gradually becomes straight, or nearly- 

 straight, as it becomes fully developed. The axis is capillary, the 

 common canal slender and very much narrower than in the normal 

 form. The breadth of the fully grown portion of the stipe is one 

 line or rather more. The cellules are long, triangular, and pointed, 

 the base resting upon the common canal, and the cell-mouth being 

 at the apex, from 20 to 30 in an inch, nearly at right angles to the 

 axis, or directed slightly upwards, their upper and lower margins 

 being subparallel and of nearly equal length ; sometimes the 

 breadth of the cellules is tolerably imiform, till close upon the cell- 

 mouth, being about ^ of an inch near the middle ; sometimes, 

 however, the inferior margin is considerably inclined to the axis, in 

 which case the base of the cellule is expanded, and its form becomes 

 more distinctly triangular ; sometimes, again, the cell-mouths are 

 deflexed ; but in no case have they ever been observed to be provided 

 with spines. The proximal cellules have mostly the same characters 

 as those of the older portion of the stipe, except that they are 

 smaller and are placed at a greater relative distance from one an- 

 other. So much is this occasionally the case, that the proximal 

 extremity may assume the characters of a Rastrites, and might, if 

 observed as a fragment, be mistaken for such. 



Most specimens average from ^ to 1 inch in length ; but some 

 attain a very much gi'cater length, though perfect examples can 

 seldom be met with. Like the normal form this variety sometimes 

 occurs rolled up into a spiral, the coils of which lie in one plane. 

 Besides this, numerous variations of a minor and unimportant cha- 

 racter occur ; but the general features of the variety are very dis- 

 tinct. 



Log. Common in the Upper Llandeilo rocks of Dumfriesshire, and 

 in the Coniston Flags of Skelgill Eeck, near Ambleside, and Mose- 

 dale in Long Sleddale. 



Graptolites EiMBRiATUS, Nich. PI. XX. figs. 3—5. 



Stipe simple, monoprionidian, about one line in breadth in the 

 adult portion, and of unknown length, the base being slender and 

 curved. The axis is capillary. The common canal is weU marked, 

 though narrow. The cellules are in contact for the inner half or 

 tbird of their length, at right angles to the axis, or directed 

 very sHghtly upwards, triangular, pectinated, and extremely closely 

 arranged, being about 30 in the space of an inch; their breadth 

 at the base is about -gij of an inch, gradually dimiaishing to- 

 wards the apex, which is either rounded off or somewhat acutely 

 pointed, but which is never deflexed or provided with spines. The 

 base is curved, the youngest portion closely resembling the proximal 

 extremity of G. Sedgwickii, var. triangidatus ; the cellules, however, 

 very rapidly become broader and more closely set. 



6r. fimhriatus cannot be confounded with any Graptohte with 

 which I am acquainted, and can be readily recognized even in small 

 fragments. It is allied to G, Sedgwickii, Portl., in its orcUnary form, 



